Initial patient testing of iPAM - a robotic system for Stroke rehabilitation

Abstract

iPAM is a dual robotic system currently being developed in the UK under a NHS New and Emerging Applications of Technologies (NEAT) grant. The aim of the system is to provide assistive upper-limb therapeutic excercise for post-stroke rehabilitation. iPAM features two co-ordinated, pneumatically-actuated robotic arms which attach to the patient's forearm and upper-arm to provide assistance, mimicking the intervention of a physiotherapist. The system design and manufacture has been completed and the robot installed at a local hospital (St Mary's, Leeds PCT, UK) inside a community rehabilitation unit. The controller is currently developed and 'tuned' to provide gravity compensation for robots, removing any potentially damaging loads on the patient arm. The control scheme has been tested in simulation and using a mechanical arm model to ensure safe operation.Two small scale trials have been conducted to assess two facets of the robot design; firstly the mechanical design of the system to unimpede normal arm movement and secondly, its ability to provide varying levels of lift to the patient's arm to increase range of movement. The former of these trials compares free arm movement in healthy volunteers and Stroke patients with that when attached to iPAM. The robot was configured to compensate for its own weight, so the human upper-limb was unloaded. It was found that the robot had no significant affect on movement patterns. The second group of patient trials evaluated the operation of various levels of assistance against gravity. Patients were asked to point to a target with varying degrees of 'lift' applied to their upper and lower arm. In those patients with significant upper-limb impairment it was found that higher values of 'lift' improved the extent of reach but altered the movement pattern. Results from the trials demonstrated the suitability of certain modes of operation depending on the severity of patient disability.

A Methodology to Quantify Alterations in Human Upper Limb Movement During Co-Manipulation With an Exoskeleton

“…Three of them are under evaluation for shoulder-elbow coordination training in healthy subjects and stroke patients. The iPAM 3D rehabilitation robot is composed of two pneumatic robots controlling the forearm and the upper arm [11]. The ArMin robot [12] is a haptic robot with semi-exoskeleton kinematics with four active (shoulder and elbow) and two passive degrees of freedom.…”

Pneumatic robotic systems for upper limb rehabilitation

“…The iPam robot was installed in the local hospital of St Mary in Leeds PCT in the UK, within the rehabilitation unit in order to obtain clinical results in trials with patients with disabilities. The test demonstrated the suitability of different modes depending on the severity of patients disabilities [16]. The main advantages of this robot are: comfort, safety, and a simple system to attach to human arms.…”

Developing a user interface for the iPAM stroke rehabilitation system

“…9. Shoulder abduction, elevation and protraction [16] The knowledge of performance feedback was given as a message similar to what a physiotherapist would say to a patient during normal therapy practice, as an addition to the attempt feedback, see Fig. 10.…”